Keyswitch structure and keyboard therewith

ABSTRACT

A keyswitch structure includes a switch and a multilayer structure above the switch. The multilayer structure includes an inner flexible layer, a rigid light-transmissive cover sheet, and a flexible light-transmissive layer. The inner flexible layer has a keycap portion and a connection portion extending outward from the keycap portion. The keycap portion is located above the switch and forms a spatial character structure. The rigid light-transmissive cover sheet is disposed on the keycap portion and covers the spatial character structure. The flexible light-transmissive layer covers the inner flexible layer and the rigid light-transmissive cover sheet. A keyboard includes the keyswitch structure and a device casing carrying the keyswitch structure. The multilayer structure is fixed to the device casing. The rigid light-transmissive cover sheet is harder than the flexible light-transmissive layer and structurally protects the spatial character structure from being damaged when the keyswitch structure is pressed.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a keyswitch structure and a keyboard,and more particularly to a keyswitch structure with protective outerlayer and a keyboard with the keyswitch structure.

2. Description of the Prior Art

Common keyboards have a plurality of keycaps for users to press forinput. The keycap usually has some characters (including text, symbols,and so on) thereon, for users to recognize and press the keycap quicklyand correctly. The Characters can be formed by printing, engraving,hollowed-out layered structures, etc., and have a spatial structure.When a finger touches and presses the keycap, the finger may rub thecharacters. After long-term rubbing, the characters may be damaged oreven disappear. Some keyboards have a protective outer layer that coversall keycaps. However, when the finger touches and presses the protectiveouter layer corresponding to the keycap to be pressed, the portion ofthe protective outer layer may still rub the characters on the keycap.Similarly, after long-term rubbing, the characters will still be damagedor even disappear.

SUMMARY OF THE INVENTION

An objective of the invention is to provide a keyswitch structure, whichuses a rigid light-transmissive cover sheet to cover a characterstructure to protect the character structure.

A keyswitch structure according to the invention includes a switch and amultilayer structure disposed above the switch. The multilayer structureincludes an inner flexible layer, a rigid light-transmissive coversheet, and a flexible light-transmissive layer. The inner flexible layerhas a keycap portion and a connection portion extending outward from thekeycap portion. The keycap portion is located above the switch and formsa spatial character structure. The rigid light-transmissive cover sheetis disposed on the keycap portion and covers the spatial characterstructure. The flexible light-transmissive layer covers the innerflexible layer and the rigid light-transmissive cover sheet. Thereby,the rigid light-transmissive cover sheet can protect spatial characterstructure from structural damage caused by rubbing when the flexiblelight-transmissive layer is pressed by a finger of a user.

An objective of the invention is to provide a keyboard, which includesthe above keyswitch structure and therefore can use the rigidlight-transmissive cover sheet to protect the character structure.

A keyboard according to the invention includes a keyswitch structure anda device casing carrying the keyswitch structure. The keyswitchstructure includes a switch and a multilayer structure disposed abovethe switch. The multilayer structure is fixed to the device casing andincludes an inner flexible layer, a rigid light-transmissive coversheet, and a flexible light-transmissive layer. The inner flexible layerhas a keycap portion and a connection portion extending outward from thekeycap portion. The keycap portion is located above the switch and formsa spatial character structure. The rigid light-transmissive cover sheetis disposed on the keycap portion and covers the spatial characterstructure. The flexible light-transmissive layer covers the innerflexible layer and the rigid light-transmissive cover sheet. Similarly,the rigid light-transmissive cover sheet can protect spatial characterstructure from structural damage caused by rubbing when the flexiblelight-transmissive layer is pressed by a finger of a user.

These and other objectives of the present invention will no doubt becomeobvious to those of ordinary skill in the art after reading thefollowing detailed description of the preferred embodiment that isillustrated in the various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is schematic diagram illustrating a keyboard according to a firstembodiment.

FIG. 2 is a partially-exploded view of the keyboard in FIG. 1.

FIG. 3 is an exploded view of a multilayer structure in FIG. 2.

FIG. 4 is a sectional view of the keyboard in FIG. 1 along the line X-X.

FIG. 5 is a sectional view of the keyboard in FIG. 4 when a first keycapthereof is pressed.

FIG. 6 is schematic diagram illustrating a keyboard according to asecond embodiment.

FIG. 7 is a sectional view of the keyboard in FIG. 6 along the line Y-Y.

FIG. 8 is a sectional view of a variant of the keyboard in FIG. 4.

FIG. 9 is a sectional view of a variant of the keyboard in FIG. 4.

FIG. 10 is a sectional diagram illustrating a layered structure forforming the multilayer structure in FIG. 2.

FIG. 11 is a sectional diagram illustrating another layered structurefor forming the multilayer structure in FIG. 2.

FIG. 12 is a sectional diagram illustrating the combination of thelayered structures in FIG. 10 and FIG. 11.

FIG. 13 is a sectional diagram illustrating the combination of thelayered structures in FIG. 12 when being shaped.

DETAILED DESCRIPTION

Please refer to FIG. 1 to FIG. 4. A keyboard 1 according to a firstembodiment includes a keyboard body 12, a multilayer structure 14, and alower flexible layer 16. The multilayer structure 14 and the lowerflexible layer 16 are disposed on the upper and lower sides of thekeyboard body 12 respectively and are joined to completely encapsulatethe keyboard body 12 to produce waterproof and dustproof effects. Themultilayer structure 14 is flexible, so that users can implement inputoperations on the keyboard body 12 by pressing the multilayer structure14.

The keyboard body 12 includes a device casing 122, and a bottom plate124, a plurality of keycaps (including a first keycap 126 a and a secondkeycap 126 b), a plurality of lift mechanisms (including a first liftmechanism 128 a and a second lift mechanism 128 b), a switch circuitboard 130, and a plurality of resilient restoration parts (including afirst resilient restoration part 132 a and a second resilientrestoration part 132 b) which are carried by the device casing 122. Thedevice casing 122 includes an upper casing 1222 and a lower casing 1224.The upper casing 1222 and the lower casing 1224 are connected to form anaccommodating space 122 a. The bottom plate 124 is placed on the lowercasing 1224 in the accommodating space 122 a. The plurality of keycapsare disposed above the bottom plate 124 and exposed from the uppercasing 1222. The plurality of lift mechanisms are connected to andbetween the keycaps and the bottom plate 124, so that the plurality ofkeycaps can move up and down relative to the bottom plate 124 in avertical direction Dv (indicated by a double-headed arrow). Each keycapcorresponds to one lift mechanism, e.g., scissors supports, butterflysupports, or other mechanisms capable of moving the corresponding keycapup and down. In practice, the lift mechanism of the longer keycaps (suchas the space bar, the enter key, the backspace key, the shift key) canbe achieved by a plurality of scissors supports, butterfly supports, ora combination thereof. The switch circuit board 130 is placed on thebottom plate 124 in the accommodating space 122 a and has a plurality ofswitches (including a first switch 130 a and a second switch 130 b).Each switch corresponds to one keycap. In practice, the longer keycapcan correspond to multiple switches. The plurality of resilientrestoration parts are disposed between the plurality of keycaps and thebottom plate 124 in the accommodating space 122 a. Each resilientrestoration part corresponds to one keycap. In practice, the longerkeycap can correspond to multiple resilient restoration parts. Theresilient restoration part can be squeezed (e.g. by the correspondingdownwardly moving keycap) to elastically deform. The resilience of thesqueezed resilient restoration part can drive the corresponding keycapto move upward and return to its original position.

Therein, the upper casing 1222 is a structural frame. The first keycap126 a is located above the first switch 130 a and exposed from a firstwindow 1222 a of the upper casing 1222 (which communicates with theaccommodating space 122 a). The first lift mechanism 128 a is connectedto and between the first keycap 126 a and the bottom plate 124. Thefirst resilient restoration part 132 a is located between the firstkeycap 126 a and the first switch 130 a. When the first keycap 126 amoves toward the first switch 130 a in the vertical direction Dv (e.g.,by a user pressing the first keycap 126 a through the multilayerstructure 14), the first keycap 126 a squeezes the first resilientrestoration part 132 a to trigger the first switch 130 a. When the firstkeycap 126 a is no longer pressed, the first resilient restoration part132 a will rebound to drive the first keycap 126 a to move upward andreturn to its original position. Similarly, the second keycap 126 b islocated above the second switch 130 b and exposed from a second window1222 b of the upper casing 1222 (which communicates with theaccommodating space 122 a). The second lift mechanism 128 b is connectedto and between the second keycap 126 b and the bottom plate 124. Thesecond resilient restoration part 132 b is located between the secondkeycap 126 b and the second switch 130 b. When the second keycap 126 bmoves toward the second switch 130 b in the vertical direction Dv, thesecond keycap 126 b squeezes the second resilient restoration part 132 bto trigger the second switch 130 b. When the second keycap 126 b is nolonger pressed, the second resilient restoration part 132 b will reboundto drive the second keycap 126 b to move upward and return to itsoriginal position. Furthermore, in the first embodiment, the projectionof the first keycap portion 1422 of the multilayer structure 14 (inwhich the first keycap portion 1422 is the portion of the inner flexiblelayer 142 corresponding to the first keycap 126 a) on the upper casing1222 in the vertical direction Dv is within the first window 1222 a. Theprojection of the second keycap portion 1424 of the multilayer structure14 (in which the second keycap portion 1424 is the portion of the innerflexible layer 142 corresponding to the second keycap 126 b) on theupper casing 1222 in the vertical direction Dv is within the secondwindow 1222 b.

Furthermore, in the first embodiment, the switch circuit board 130 isachieved by a membrane circuit board which includes an upper circuitsubstrate, a lower circuit substrate, and an intermediate insulationsheet disposed between the upper circuit substrate and the lower circuitsubstrate. The switch is achieved by contacts oppositely disposed on theupper circuit substrate and the lower circuit substrate; forsimplification of drawing, the switch is shown by a single block in thefigures. In practice, the switch circuit board 130 may also be achievedby other structures, e.g., disposing a tactile switch on a printedcircuit board or flexible circuit board. For another example, oppositecontacts are formed on a circuit board as a switch. The resilientrestoration part has a conductive portion, so that when the resilientrestoration part is squeezed downward, the conductive portion canconduct the contacts. In addition, in practice, the switch may betriggered by other structures. For example, in the view point of FIG. 4,the first switch 130 a is offset from the middle (so as not to becovered by the first resilient restoration part 132 a). The first keycap126 a has a downward protrusion corresponding to the first switch 130 a,so that when the first keycap 126 a moves downward, the protrusion cantrigger the first switch 130 a. For another example, the protrusion inthe above example may be disposed on the first lift mechanism 128 a(e.g., one of the supports of the scissors support) alternatively, sothat when the first keycap 126 a moves downward, the first keycap 126 adrives the first lift mechanism 128 a to fold so as to make theprotrusion trigger the first switch 130 a.

As shown by FIG. 3 and FIG. 4, the multilayer structure 14 includes aninner flexible layer 142, a flexible light-transmissive layer 144stacked on the inner flexible layer 142, and a first rigidlight-transmissive cover sheet 146 and a second rigid light-transmissivecover sheet 148 which are stacked between the inner flexible layer 142and the flexible light-transmissive layer 144. The rigidity of the firstrigid light-transmissive cover sheet 146 and the second rigidlight-transmissive cover sheet 148 is greater than that of the innerflexible layer 142. The inner flexible layer 142 has a first keycapportion 1422, a second keycap portion 1424, and a connection portion1426 which directly connects the first keycap portion 1422 and thesecond keycap portion 1424. In structural logic, the connection portion1426 can be considered to extend outward from the first keycap portion1422 (relative to the first keycap portion 1422) and can be consideredto also extend outward from the second keycap portion 1424 (relative tothe second keycap portion 1424). Furthermore, in the first embodiment,the connection portion 1426 surrounds the first keycap portion 1422 andthe second keycap portion 1424 (as shown by FIG. 3). The first keycapportion 1422 covers the first keycap 126 a (i.e., located above thefirst switch 130 a) and forms a first spatial character structure 1422a; the second keycap portion 1424 covers the second keycap 126 b (i.e.,located above the second switch 130 b) and forms a second spatialcharacter structure 1424 a. Therein, the first spatial characterstructure 1422 a and the second spatial character structure 1424 a arerepresented by round holes for simplification of drawing. The firstrigid light-transmissive cover sheet 146 is disposed above the firstkeycap portion 1422 and covers the first spatial character structure1422 a. The second rigid light-transmissive cover sheet 148 is disposedon the second keycap portion 1424 and covers the second spatialcharacter structure 1424 a. The flexible light-transmissive layer 144covers the inner flexible layer 142, the first rigid light-transmissivecover sheet 146, and the second rigid light-transmissive cover sheet148.

Thereby, when the user presses the first keycap 126 a, the user's fingeractually touches the portion of the multilayer structure 14 (or theflexible light-transmissive layer 144) corresponding to the first keycap126 a. Even during the pressing process, the finger may rub themultilayer structure 14. Under the protection of the first rigidlight-transmitting cover sheet 146, the first spatial characterstructure 1422 a will not be affected by the rubbing of the finger, atleast reducing structural damage to the first spatial characterstructure 1422 a (including structural deformation of the first spatialcharacter structure 1422 a) caused by rubbing of the finger. Similarly,the second rigid light-transmissive cover sheet 148 also has the sameprotective effect on the second spatial character structure 1424 a,which will not be repeated. In addition, for simplification of drawingand description, the first embodiment is based on that the first keycap126 a and the second keycap 126 b have the first spatial characterstructure 1422 a and the second spatial character structure 1424 arespectively; however, it is not limited thereto in practice. Forexample, the multilayer structure 14 may has a spatial characterstructure and a corresponding rigid light-transmissive cover sheet foreach keycap, which will not described in addition.

Furthermore, as shown by FIG. 2 to FIG. 5, in the first embodiment, thefirst keycap 126 a has a horizontal keycap surface 1262 a. The firstkeycap portion 1422 is fixed on the horizontal keycap surface 1262 a.The projection of the first rigid light-transmissive cover sheet 146 onthe first keycap 126 a in the vertical direction Dv is within thehorizontal keycap surface 1262 a; that is, the first rigidlight-transmissive cover sheet 146 is smaller than the horizontal keycapsurface 1262 a. In practice, the outer diameter of the first rigidlight-transmissive cover sheet 146 can be designed to be smaller thanthe outer diameter of the horizontal keycap surface 1262 a by about 0.4mm, that is, 0.2 mm on one side. It can meet most of the assemblytolerance requirements, so that after the multilayer structure 14 isassembled to the keyboard body 12, the first rigid light-transmissivecover sheet 146 can effectively fall into the horizontal keycap surface1262 a, avoiding the first rigid light-transmissive cover sheet 146 fromprotruding from the horizontal keycap surface 1262 a in a horizontaldirection Dh (indicated by a double-headed arrow in the figures, whichis perpendicular to the vertical direction Dv) to affect the user'spressing feeling. The first keycap 126 a also has a keycap fringe 1264 awhich bends downward and extends from the horizontal keycap surface 1262a. The multilayer structure 14 (or the inner flexible layer 142 thereof)and the keycap fringe 1264 a are separable, so that when the firstkeycap 126 a is pressed, the multilayer structure 14 can be smoothly andelastically deformed and will not cause excessive pulling on the firstkeycap 126 a and affect the up and down movement of the first keycap 126a, as shown by FIG. 5. Furthermore, in the first embodiment, when thefirst keycap 126 a is not pressed yet, there is a gap G1 between thefirst keycap portion 1422 and the keycap fringe 1264 a in the horizontaldirection Dh.

Furthermore, as shown by FIG. 2 to FIG. 4, the multilayer structure 14is located above the upper casing 1222 and fixed to an outer surface1222 c of the upper casing 1222. The lower flexible layer 16 is locatedunder the lower casing 1224. The periphery 14 a of the multilayerstructure 14 and the periphery 16 a of the lower flexible layer 16 arejoined (for example, but not limited to by glue) to encapsulate thedevice casing 122. Moreover, in the first embodiment, the multilayerstructure 14 also includes a rigid frame sheet 150. The inner flexiblelayer 142 is stacked on the rigid frame sheet 150, for example, but notlimited to by combining the both with an adhesive layer 151 a (onlyshown in FIG. 4 and FIG. 5 for simplification of drawing). Themultilayer structure 14 is fixed to the upper casing 1222 through therigid frame sheet 150 (for example, but not limited to by combining theboth with an adhesive layer 151 b, only shown in FIG. 4 and FIG. 5 forsimplification of drawing). Therein, the rigid frame sheet 150 has afirst through hole 150 a and a second through hole 150 b. The connectionportion 1426 is fixed on the rigid frame sheet 150. The rigid framesheet 150 has a greater rigidity than the inner flexible layer 142 andthe flexible light-transmissive layer 144, so the structural rigidity ofthe multilayer structure 14 is increased. The projection of the firstkeycap portion 1422 on the rigid frame sheet 150 in the verticaldirection Dv is within the first through hole 150 a. The projection ofthe second keycap portion 1424 on the rigid frame sheet 150 in thevertical direction Dv is within the second through hole 150 b. Thereby,when the first keycap 126 a is pressed, the multilayer structure 14 canbe smoothly and elastically deformed; the same is true for the secondkeycap 126 b, which will not be described in addition.

Furthermore, in the first embodiment, the inner flexible layer 142 ismade of an opaque material, for example but not limited to wovenfabrics, thermoplastic polyurethanes (TPU), polyurethane (PU) and so on.The first spatial character structure 1422 a is a holed structure. Thefirst keycap 126 a is light-transmissive; for example, the entire firstkeycap 126 a may be made of a light-transmissive material, or only theportion of the first keycap 126 a corresponding to the holed structureis light-transmissive. The keyboard body 12 includes a light source 134a (or referred to as a first light source 134 a), disposed under thefirst keycap 126 a corresponding to the first spatial characterstructure 1422 a. Light emitted by the light source 134 a can travelupward to pass through the first keycap 126 a, the first spatialcharacter structure 1422 a, the first rigid light-transmissive coversheet 146, and the flexible light-transmissive layer 144 to be emittedfrom the multilayer structure 14, which can provide the user with avisual effect. Similarly, the second spatial character structure 1424 amay also be a holed structure. The second keycap 126 b maylight-transmissive. The keyboard body 12 includes another light source134 b (or referred to as a second light source 134 b), disposed underthe second keycap 126 b corresponding to the second spatial characterstructure 1424 a. Light emitted by the light source 134 b can travelupward to pass through the second keycap 126 b, the second spatialcharacter structure 1424 a, the second rigid light-transmissive coversheet 148, and the flexible light-transmissive layer 144 to be emittedfrom the multilayer structure 14, which can provide the user with visualeffects. The first and second light sources 134 a and 134 b (for examplebut not limited to light-emitting diodes) are disposed on a printedcircuit board or flexible circuit board under the bottom plate 124.Therein, in order to enable the light emitted by the first and secondlight sources 134 a and 134 b to travel upward, the bottom plate 124forms holes corresponding to the light sources 134 a and 134 b. Inpractice, the light sources 134 a and 134 b may also be integrated ontothe switch circuit board 130. In addition, if the first and secondresilient restoration parts 132 a and 132 b covers the first and secondlight sources 134 a and 134 b, the first and second resilientrestoration parts 132 a and 132 b may be made of a light-transmissivematerial, for example but not limited to light-transmissive rubberdomes.

Furthermore, in practice, the profile of the first spatial characterstructure 1422 a may be text, symbols, numbers, graphics, etc. Thesecond spatial character structure 1424 a may also be the same, whichwill not be repeated. In addition, in practice, the first spatialcharacter structure 1422 a is not limited to provide the user with avisual effect through light transmission. For example, the first spatialcharacter structure 1422 a is achieved by a recess in which a lightreflective material is disposed. For this instance, the first keycap 126a does not need to be light transmissive; therein, the recess may beformed by the first keycap portion 1422 alone (e.g. by embossing thefirst keycap portion 1422), or may be formed jointly by the first keycap126 a (or the horizontal keycap surface 1262 a thereof) and the openingformed by the first keycap portion 1422. In addition, the inner flexiblelayer 142 is opaque and therefore can be used as a light-blocking layerwhich blocks light (from the light sources 134 a and 134 b) escapingfrom the periphery of the first keycap 126 a and the second keycap 126b.

In the first embodiment, the first keycap portion 1422 is fixed on thehorizontal keycap surface 1262 a by means of glue (for example but notlimited to an adhesive layer 143). The connection portion 1426 is alsofixed on the rigid frame sheet 150 by means of glue (i.e., by theadhesive layer 151 a). The first rigid light-transmissive cover sheet146 is also fixed on the first keycap portion 1422 by means of glue (forexample but not limited to an adhesive layer 147). Therein, the aboveadhesive layers 143, 147, 151 a and 151 b are shown only in FIG. 4 andFIG. 5 for simplification of drawing; however, it is not limitedthereto. For example, the first rigid light-transmissive cover sheet 146(and the second rigid light-transmissive cover sheet 148) can beeffectively fixed through the combination of the flexiblelight-transmissive layer 144 and the inner flexible layer 142. Theflexible light-transmissive layer 144 may be but not limited tolight-transmissive silicone. The first rigid light-transmissive coversheet 146, the second rigid light-transmissive cover sheet 148, and therigid frame sheet 150 may be but not limited to polyethyleneterephthalate (PET), polycarbonate (PC), FR4 epoxy glass fibers, etc.The adhesive layers 143 and 147 also use appropriate materials as needed(for example, light transmission is required).

In addition, in the first embodiment, the keyboard 1 includes aplurality of keycaps, and thus the structure of the keyboard 1 ismultiple keyswitch structures. In logic, one keycap and thecorresponding structure can be regarded as a single-key keyswitchstructure, e.g. the single-key keyswitch structures 10 a and 10 bindicated by dashed frames in FIG. 4. The combination of the both can beregarded as a double-key keyswitch structure. In practice, the abovesingle-key keyswitch structures 10 a and 10 b or the double-keykeyswitch structure can also be applied to other applications, e.g.button switches, keys or buttons on the device control panel, etc. Thedescription of the variants of keyboard 1 in the specification alsoapplies herein, and will not be repeated in addition. It is noticed thatin the keyboard 1, the structural frame is used directly as the uppercasing 1222. The structural frame is contained in the device casing 122and becomes apart of the device housing 122. However, it is not limitedthereto. In practice, the structural frame may not be contained in thedevice casing 122, and is not a part of the device housing 122; that is,the portions of the upper casing 1222 inside the dashed frames in FIG. 4are not regarded as a part of the device casing 122. Correspondingly,the multilayer structure 14 is fixed to the structural frame. Thestructural frame has a first window and a second window. The projectionof the first keycap portion 1422 on the structural frame in the verticaldirection Dv is within the first window. The projection of the secondkeycap portion 1424 on the structural frame in the vertical direction Dvis within the second window.

Furthermore, in the first embodiment, the multilayer structure 14 coversthe upper casing 1222; however, it is not limited thereto in practice.For example, as shown by FIG. 6 and FIG. 7, a keyboard 3 according to asecond embodiment is structurally similar to the keyboard 1, so thekeyboard 3 uses the reference numbers of the keyboard 1 in practice. Inthe keyboard 3, the multilayer structure 34 covers the plurality ofkeycap and is fixed on an inner surface 1222 d of the upper casing 1222;that is, the multilayer structure 34 is disposed in the device casing122 and the portions thereof corresponding to the keycaps are exposed orprotrudes from the upper casing 1222. For example, the first keycapportion 1422 protrudes from the first window 1222 a, the second keycapportion 1424 protrudes from the second window 1222 b, and the connectionportion 1426 is located under the upper casing 1222. Therein, themultilayer structure 34 adheres to the inner surface 1222 d through theadhesive layer 145 of the flexible light-transmissive layer 144;however, it is not limited thereto. For example, the portion of themultilayer structure 34 located in the accommodating space 122 a may beclamped by the upper casing 1222 and the lower casing 1224 (e.g. byusing a upwardly-protruding structure disposed on the lower casing 1224to abut against the multilayer structure 34), which also can achieve theeffect of fixing the multilayer structure 34 and the device casing 122.For another example, in the multilayer structure 34, the rigid framesheet 150 is disposed on the flexible light-transmissive layer 144alternatively. The modified multilayer structure 34 may be fixed toinner surface 1222 d through the rigid frame sheet 150 (similarly, whichmay be achieved by means of glue).

Furthermore, in the first embodiment, the keycap (e.g. the first keycap126 a) is supported by a lift mechanism (e.g. the first lift mechanism128 a) and a resilient restoration part (e.g. the first resilientrestoration part 132 a); however, it is not limited thereto in practice.For example, the first keycap 126 a is supported only by the firstresilient restoration part 132 a. For another example, if the multilayerstructure 14 itself can maintain the shape of the keycap (for example,the first rigid light-transmissive cover sheet 146 can increase thestructural rigidity), the can be further omitted so that the firstresilient restoration part 132 a directly abuts the first keycap portion1422, as shown by FIG. 8. For another example, if the multilayerstructure 14 can provide sufficient structural flexibility, the firstresilient restoration part 132 a can be further omitted, as shown byFIG. 9. In this instance, the multilayer structure 14′ is a variant ofthe multilayer structure 14 of the above keyboard 1. Compared with themultilayer structure 14, the multilayer structure 14′ further includes aprotrusion 152 which protrudes toward the first switch 130 a. When theportion of the multilayer structure 14′ corresponding to the firstkeycap portion 1422 is pressed, the protrusion 152 moves downward totrigger the first switch 130 a. In practice, the protrusion 152 may befixed to the inner flexible layer 142 by means of glue, or theprotrusion 152 is structurally integrated into the inner flexible layer142. For example, the inner flexible layer 142 is shaped by hot-pressingto form the protrusion 152.

In addition, in the keyboard 1, the multilayer structure 14 may beformed by, but not limited to, laminating sheet materials and shaping inpractice. For example, as shown by FIG. 10 (in which the cross sectionis not hatched for simplification of drawing), a transfer film 1400 isprepared. The transfer film 1400 carries a light-transmissive film 1402used for forming the first rigid light-transmissive cover sheet 146 andthe second rigid light-transmissive cover sheet 148. Then, an adhesivelayer 1404 used for forming the adhesive layer 147 is formed on thelight-transmissive film 1402 (e.g. by hot melt glue, double-sided glue,or other glues). The light-transmissive film 1402 (and the adhesivelayer 1404 thereon) is processed to form the first rigidlight-transmissive cover sheet 146 and the second rigidlight-transmissive cover sheet 148 (in which the adhesive layer 1404after processed forms the adhesive layer 147), e.g. by removingunnecessary portions (indicated by dashed frames in the figure) throughlaser.

As shown by FIG. 11 (in which the cross section is not hatched forsimplification of drawing), a film 1406 used for forming the rigid framesheet 150 is prepared. An adhesive layer 1408 (e.g. by hot melt glue,double-sided glue, or other glues) used for forming the adhesive layer151 a is formed on the film 1406. A film 1410 used for forming the innerflexible layer 142 adheres to the adhesive layer 1408. Therein, the film1406 (together with the adhesive layer 1408) may be processed first toform the rigid frame sheet 150 (e.g. by punching to remove unnecessaryportions which are indicated by dashed frames in the figure). Then, afilm 1410 adheres to the adhesive layer 1408. Alternatively, after thefilm 1410 adheres to the adhesive layer 1408, the combination isprocessed to form the rigid frame sheet 150 (e.g. by using laser toremove unnecessary portions which are indicated by dashed frames in thefigure).

As shown by FIG. 12 (in which the cross section is not hatched forsimplification of drawing), after the layered structures in FIG. 10 andFIG. 11 are joined through the adhesive layer 1404, the transfer film1400 is removed. Then, a layer of glue 1412 is coated on the combinationof the layered structures (i.e. the first rigid light-transmissive coversheet 146 and the second rigid light-transmissive cover sheet 148thereof). As shown by FIG. 13, the structure in FIG. 12 is placed in ashaping mold 4 and then is compressed and heated (e.g. 120 degreesCelsius for 120 seconds) through the shaping mold 4 to form the flexiblelight-transmissive layer 144. At this moment, the shaped layeredstructure has carried out most of the multilayer structure 14. Then, thefirst keycap portion 1422 and the second keycap portion 1424 (formed bythe film 1410) in the shaped layered structure is processed by laserengraving (on the portions indicated by dashed frames in FIG. 13) toform the first spatial character structure 1422 a and the second spatialcharacter structure 1424 a. Therein, in practice, the glue 1412 may beformed on the bonded layered structures in FIG. 12 by injection, e.g.through the shaping mold 4 that is made into an injection mold. Inaddition, in the keyboard 1, the multilayer structure 14 is fixed on theouter surface 1222 c of the upper casing 1222, so the adhesive layer 151b is formed on the rigid frame sheet 150 of the multilayer structure 14that is shaped through the shaping mold 4, so as to adhere to the outersurface 1222 c. Or, the adhesive layer 151 b is formed on the outersurface 1222 c alternatively, for the rigid frame sheet 150 to adherethereto. Similarly, the adhesive layer 143 is formed on the surface,toward the keycap, of the inner flexible layer 142 of the multilayerstructure 14 that is shaped through the shaping mold 4, so as to adhereto the first keycap 126 a and the second keycap 126 b. Or, the adhesivelayer 143 is formed on the first keycap 126 a and the second keycap 126b alternatively, for the inner flexible layer 142 to adhere thereto.Furthermore, the above multilayer structures 14′ and 34 can also be madein a similar manner, which will not be described in addition.

As described above, when the user presses the keycap, the user's fingeractually touches the portion of the multilayer structure (or theflexible light-transmissive layer) corresponding to the keycap. Evenduring the pressing process, the finger may rub the multilayerstructure. Under the protection of the rigid light-transmitting coversheet, the spatial character structure will not be affected by therubbing of the finger, at least greatly reducing structural damage tothe spatial character structure (including structural deformation of thefirst spatial character structure) caused by rubbing of the finger.

Those skilled in the art will readily observe that numerousmodifications and alterations of the device and method may be made whileretaining the teachings of the invention. Accordingly, the abovedisclosure should be construed as limited only by the metes and boundsof the appended claims.

What is claimed is:
 1. A keyswitch structure, comprising: a firstswitch; and a multilayer structure, disposed above the first switch, themultilayer structure comprising: an inner flexible layer, having a firstkeycap portion and a connection portion extending outward from the firstkeycap portion, the first keycap portion being located above the firstswitch and forming a first spatial character structure; a first rigidlight-transmissive cover sheet, disposed on the first keycap portion andcovering the first spatial character structure; and a flexiblelight-transmissive layer, covering the inner flexible layer and thefirst rigid light-transmissive cover sheet.
 2. The keyswitch structureaccording to claim 1, further comprising a first keycap, disposed abovethe first switch and under the multilayer structure, wherein the firstkeycap portion covers the first keycap, and the first keycap moves in avertical direction toward the first switch to trigger the first switch.3. The keyswitch structure according to claim 2, wherein the firstkeycap has a horizontal keycap surface, the first keycap portion isfixed on the horizontal keycap surface, and a projection of the firstrigid light-transmissive cover sheet on the first keycap in the verticaldirection is within the horizontal keycap surface.
 4. The keyswitchstructure according to claim 3, wherein the first keycap has a keycapfringe, the keycap fringe bends downward and extends from the horizontalkeycap surface, and the multilayer structure and the keycap fringe areseparable.
 5. The keyswitch structure according to claim 4, wherein whenfirst keycap is not pressed, there is a gap between the first keycapportion and the keycap fringe in a horizontal direction.
 6. Thekeyswitch structure according to claim 1, wherein the multilayerstructure comprises a protrusion that protrudes toward the first switch,and a portion of the multilayer structure corresponding to the firstkeycap portion is pressed to move the protrusion downward to trigger thefirst switch.
 7. The keyswitch structure according to claim 1, furthercomprising a resilient restoration part, disposed between the firstkeycap portion and the first switch, wherein a portion of the multilayerstructure corresponding to the first keycap portion is pressed, so thatthe multilayer structure touches and squeezes the resilient restorationpart to trigger the first switch.
 8. The keyswitch structure accordingto claim 1, wherein the connection portion surrounds the first keycapportion.
 9. The keyswitch structure according to claim 1, wherein themultilayer structure comprises a rigid frame sheet, the rigid framesheet has a first through hole, the connection portion is fixed on therigid frame sheet, and a projection of the first keycap portion on therigid frame sheet in a vertical direction is within the first throughhole.
 10. The keyswitch structure according to claim 1, furthercomprising a second switch, wherein the inner flexible layer has asecond keycap portion, the connection portion connects the first keycapportion and the second keycap portion, the second keycap portion islocated above the second switch and forms a second spatial characterstructure, the multilayer structure comprises a second rigidlight-transmissive cover sheet disposed on the second keycap portion andcovering the second spatial character structure, the flexiblelight-transmissive layer covers the second rigid light-transmissivecover sheet, the rigid frame sheet has a second through hole, and aprojection of the second keycap portion on the rigid frame sheet in thevertical direction is within the second through hole.
 11. The keyswitchstructure according to claim 1, further comprising a structural frame,wherein the structural frame has a first window, the multilayerstructure is fixed to the structural frame, and a projection of thefirst keycap portion on the structural frame in a vertical direction iswithin the first window.
 12. The keyswitch structure according to claim11, further comprising a second switch, wherein the inner flexible layerhas a second keycap portion, the connection portion connects the firstkeycap portion and the second keycap portion, the second keycap portionis located above the second switch and forms a second spatial characterstructure, the multilayer structure comprises a second rigidlight-transmissive cover sheet disposed on the second keycap portion andcovering the second spatial character structure, the flexiblelight-transmissive layer covers the second rigid light-transmissivecover sheet, the structural frame has a second window, and a projectionof the second keycap portion on the structural frame in the verticaldirection is within the second window.
 13. The keyswitch structureaccording to claim 1, wherein the inner flexible layer is made of anopaque material.
 14. The keyswitch structure according to claim 1,wherein the first spatial character structure is a holed structure. 15.A keyboard, comprising: a keyswitch structure; and a device casing,carrying the keyswitch structure; wherein the keyswitch structurecomprises: a first switch; and a multilayer structure, disposed abovethe first switch and fixed to the device casing, the multilayerstructure comprising: an inner flexible layer, having a first keycapportion and a connection portion extending outward from the first keycapportion, the first keycap portion being located above the first switchand forming a first spatial character structure; a first rigidlight-transmissive cover sheet, disposed on the first keycap portion andcovering the first spatial character structure; and a flexiblelight-transmissive layer, covering the inner flexible layer and thefirst rigid light-transmissive cover sheet.
 16. The keyboard accordingto claim 15, wherein the device casing comprises an upper casing and alower casing, the upper casing and the lower casing are connected toform an accommodating space, the first switch is disposed in theaccommodating space, the upper casing has a first window, a projectionof the first keycap portion on the upper casing in a vertical directionis within the first window, and the multilayer structure is fixed to anouter surface of upper casing.
 17. The keyboard according to claim 16,further comprising a lower flexible layer, wherein the multilayerstructure is located above the upper casing, the lower flexible layer islocated under the lower casing, and the multilayer structure is joinedwith the lower flexible layer to encapsulate the device casing.
 18. Thekeyboard according to claim 15, wherein the device casing comprises anupper casing and a lower casing, the upper casing and the lower casingare connected to form an accommodating space, the first switch isdisposed in the accommodating space, the upper casing has a firstwindow, a projection of the first keycap portion on the upper casing ina vertical direction is within the first window, and the multilayerstructure is fixed to an inner surface of the upper casing.
 19. Thekeyboard according to claim 15, wherein the multilayer structurecomprises a rigid frame sheet, the rigid frame sheet has a first throughhole, the connection portion is fixed on the rigid frame sheet, and aprojection of the first keycap portion on the rigid frame sheet in avertical direction is within the first through hole.
 20. The keyboardaccording to claim 15, wherein the device casing forms an accommodatingspace and has first and second windows communicating with theaccommodating space, the keyswitch structure comprises a second switch,the first and second switches are disposed in the accommodating spacecorresponding to the first and second windows respectively, the innerflexible layer has a second keycap portion above the second switch, theconnection portion connects the first and second keycap portions andsurrounds the first keycap portion, a projection of the first keycapportion in a vertical direction is within the first window, and aprojection of the second keycap portion in the vertical direction iswithin the second window.